Flexible Slip Joint Apparatus for Earthquake Resistance
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Solution Overview
Problem
Conventional flexible joints in pipelines, such as bellows-type and complex joints, are inadequate in allowing large and repetitive up, down, left, and right movements due to external forces like earthquakes, leading to stress accumulation and potential leakage.
Innovation Solution
An earthquake-resistant flexible slip joint apparatus with a cylindrical joint outer part, an inner crimped portion, and a slip inner part, featuring a pressurizing space that prevents fluid leakage through elastic deformation of the inner crimped portion during movements, allowing for extensive flexibility without damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional bellows-type flexible joint is used, then the structure is simple and installation cost is low, but the elasticity is limited and the scope of applicability is extremely limited
Solution Approach 1:
The flexible joint is divided into multiple bellows sections (first bellows, second bellows, third bellows) connected in series, allowing each section to contribute to the overall elastic deformation capacity. This segmentation enables the joint to handle larger displacements and rotations while maintaining a relatively simple modular structure that is easy to manufacture and install.
Solution Approach 2:
The bellows-type flexible joint is nested within a spherical joint structure, which in turn is connected to pipe sections. This nested arrangement allows the bellows to provide elastic deformation for absorbing thermal expansion and vibration, while the spherical joint provides additional rotational freedom, thereby expanding the scope of applicability without significantly increasing structural complexity.
2Stability of the object's composition
If both ends of the bellows-type flexible joint are fixed between the pipes, then the structure is stable, but the joint could easily break when twisting occurs due to rotational force
Solution Approach 1:
The flexible joint incorporates multiple degrees of freedom through the combination of bellows expansion/contraction and spherical joint rotation. This dynamic capability allows the joint to adapt to various movement patterns (axial displacement, lateral movement, and rotation) without experiencing excessive stress concentration that would lead to breaking, while maintaining structural stability through the interconnected design.
Solution Approach 2:
The bellows sections are designed with specific geometric parameters (number of convolutions, wall thickness, material properties) that allow them to undergo controlled elastic deformation. By optimizing these parameters, the joint can absorb rotational forces and twisting moments without exceeding the material's elastic limit, thereby preventing breakage while maintaining structural integrity.
3Adaptability or versatility
If a conventional complex joint including slip joint and ball joint is used, then external forces from various directions can be sustained, but the structure is complex and manufacturing is difficult and expensive
Solution Approach 1:
The invention merges the functions of the bellows-type flexible joint (for absorbing axial thermal expansion and vibration) and the spherical joint (for allowing lateral movement and rotation) into a single integrated structure. This unified design provides multi-directional movement capability and resistance to external forces from various directions, while simplifying the overall structure compared to having separate components, thereby reducing manufacturing complexity and cost.
4Device complexity
If the bellows-type flexible joint is used for large earthquake movements, then the structure may remain simple, but the deformation extent is insufficient and fluid leakage probability increases
Solution Approach 1:
By dividing the flexible joint into multiple bellows sections connected in series, the total elastic deformation capacity is significantly increased compared to a single bellows section. Each bellows section contributes to the overall displacement absorption, allowing the joint to accommodate large movements during earthquakes while maintaining the simplicity of the bellows structure and preventing fluid leakage through the extended elastic range.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus effectively prevents fluid leakage and supports large, repetitive movements by distributing stress through elastic deformation, reducing the risk of damage and ensuring safety during external forces like earthquakes.
Implementation Method 1
the inner crimped portion is elastically deformed when the slip inner part moves in up, down, left, and right directions
Implementation Method 2
an adhesion between the inner portion and the slip inner part increases due to a pressure of a conveyed fluid, the pressure being applied via the pressurizing space
Data Source
AI summary
An earthquake-resistant flexible slip joint apparatus includes a joint outer part including an outer portion, an end connection portion, and an inner portion, and a slip inner part, wherein a pressurizing space is formed to be surrounded by the outer portion, the end connection portion, and the inner portion of the joint outer part, the inner portion includes a packing portion at a region thereof spaced apart from the end connection portion, the inner portion further includes an inner crimped portion and the packing portion, and an adhesion between the inner portion and the slip inner part increases due to a pressure of a conveyed fluid, the pressure being applied via the pressurizing space, and the inner crimped portion is elastically deformed when the slip inner part moves in up, down, left, and right directions, so that the conveyed fluid does not leak to the outside.